Control information sending method, receiving method, and device

ABSTRACT

Embodiments of the present invention provide a control information sending method, receiving method, and device. The control information sending method includes: determining a first subframe of a first radio frame on a first carrier, where the first subframe includes a control region; sending control information in the control region of the first subframe of the first radio frame to a user equipment, where the control information includes a PDCCH; and sending an ePDCCH in a second subframe of the first radio frame to the user equipment. According to the embodiments of the present invention, when control information borne on an ePDCCH cannot be sent in a first radio frame, a PDCCH can still be sent to a user equipment through a control region in a first subframe, thereby achieving purposes of performing uplink/downlink scheduling for the user equipment and downlink feedback for uplink data of the user equipment.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/672,050, filed on Mar. 27, 2015, which is a continuation ofInternational Patent Application No. PCT/CN2013/070255, filed on Jan. 9,2013, which claims priority to International Patent Application No.PCT/CN2012/082453, filed on Sep. 29, 2012. The disclosures of theaforementioned applications are hereby incorporated by reference intheir entireties.

TECHNICAL FIELD

The present invention relates to a communications technology, and inparticular, to a control information sending method, receiving method,and device.

BACKGROUND

In Long Term Evolution (LTE for short) systems of releases 8, 9, and 10,each LTE carrier is backward compatible, that is, each LTE system of alater release can support access and data transmission of a userequipment of an earlier LTE release. Each subframe of a backwardcompatible carrier has a control region. The control region is in firstn symbols of a subframe in a time domain and occupies a bandwidth of thewhole carrier in a frequency domain, where n is a natural number rangingfrom 1 to 4. The control region bears downlink control channels such asa physical downlink control channel (PDCCH for short), a physical hybridautomatic repeat request indicator channel (PHICH for short), and aphysical control format indicator channel (PCFICH for short).Demodulation of the foregoing downlink control channels is based on acell-specific reference signal (CRS for short). The CRS is used for datademodulation, time and frequency synchronization and tracking, channelinterference, radio resource management measurement, and the like, on abackward compatible carrier. When a base station has no data to be sentin a certain subframe, the base station also sends a CRS in thesubframe; therefore, the energy efficiency of the base station isrelatively low.

In Long Term Evolution-Advanced (LTE-A for short) systems of release 11and a release later than release 11, a new carrier type (NCT) isintroduced. A new carrier does not support access and data transmissionof a user equipment (UE for short) of an earlier LTE release, andsupports access and data transmission of a UE of a new release of theLTE system. It is allowed that the NCT does not have a control region ona backward compatible carrier, that is, a PDCCH is not sent, and thePDCCH is replaced by an enhanced physical downlink control channel(ePDCCH for short). Different from the PDCCH, the ePDCCH is transmittedbased on channel precoding. A resource configuration of the ePDCCH issimilar to that of the PDCCH, that is, assignment is implemented throughan RB pair. The ePDCCH is demodulated based on a UE-specific referencesignal (VERS for short).

In LTE-A systems of release 11 and a release later than release 11, theNCT does not have a control region. If an ePDCCH cannot be sent on theNCT, it is possible that the NCT cannot be used to schedule a userequipment or implement downlink feedback for uplink data of the userequipment. For example, the ePDCCH cannot be sent in a multimediabroadcast multicast service single frequency network (MBSFN for short)subframe or in special subframes in special subframe configurations 0and 5 of a time division duplex (TDD for short) system, and uplink ordownlink scheduling of the user equipment cannot be implemented.Specifically, if a multicast or broadcast service is transmitted in anMBSFN subframe, all resource block pairs (RB pair) of the currentcarrier are used for multicast or broadcast, that is, no RB pair isassigned to the ePDCCH; for special subframes in TDD special subframeconfigurations 0 and 5, a downlink timeslot part has only three symbols,and resources are few, so an ePDCCH cannot be sent.

SUMMARY

Embodiments of the present invention provide a control informationsending method, receiving method, and device, which are used to overcomethe disadvantage that a user equipment cannot be scheduled and downlinkfeedback for uplink data of the user equipment cannot be implementedwhen an ePDCCH cannot be sent.

According to a first aspect, an embodiment of the present inventionprovides a control information sending method, which includes:

determining, by a network device, a first subframe of a first radioframe on a first carrier, where the first subframe includes a controlregion, the control region is in first n symbols of the first subframe,and n is a natural number less than 5;

sending, by the network device, control information in the controlregion of the first subframe of the first radio frame to a userequipment, and sending a demodulation reference signal in the firstsubframe of the first radio frame to the user equipment, where thecontrol information at least includes a PDCCH; and

sending, by the network device, an ePDCCH in a second subframe of thefirst radio frame to the user equipment.

With reference to the first aspect, in a first possible implementationmanner, in the sending a demodulation reference signal in the firstsubframe to the user equipment, the demodulation reference signal issent only when the control information is sent; and/or, the demodulationreference signal is only used to demodulate the control information.

With reference to the first aspect or the first possible implementationof the first aspect, in a second possible implementation manner, beforethe determining a first subframe of a first radio frame on a firstcarrier, the method further includes: sending RRC dedicated signaling tothe user equipment, so as to indicate a position of the first subframeof the first radio frame on the first carrier to the user equipment.

With reference to the second possible implementation of the firstaspect, in a third possible implementation manner,

before the sending RRC dedicated signaling the user equipment, sending,by the network device, system information to the user equipment, wherethe system information is scheduled by an ePDCCH scrambled by a systeminformation radio network temporary identifier SI-RNTI;

receiving, by the network device, random access information sent by theuser equipment, where configuration information of the random accessinformation is obtained from the system information;

sending, by the network device, random access response information tothe user equipment, where the random access response information isscheduled by an ePDCCH scrambled by a random access radio networktemporary identifier RA-RNTI; and

sending RRC connection setup information to the user equipment.

According to a second aspect, the present invention further provides acontrol information receiving method, which includes:

determining, by a user equipment, a first subframe of a first radioframe on a first carrier, where the first subframe includes a controlregion, the control region is in first n symbols of the first subframe,and n is a natural number less than 5;

receiving, by the user equipment, control information, sent by a networkdevice, in the control region of the first subframe of the first radioframe, and receiving a demodulation reference signal, sent by thenetwork device, in the first subframe, where the control information atleast includes a PDCCH; and

receiving, by the user equipment, an ePDCCH, sent by the network device,in a second subframe of the first radio frame.

With reference to the second aspect, in a first possible implementationmanner, in the receiving a demodulation reference signal, sent by thenetwork device, in the first subframe, the demodulation reference signalis sent only when the control information is sent; and/or, thedemodulation reference signal is only used to demodulate the controlinformation.

With reference to the second aspect or the first possible implementationof the second aspect, in a second possible implementation manner, beforethe determining a first subframe of a first radio frame on a firstcarrier, receiving RRC dedicated signaling sent by the network device,where the RRC dedicated signaling is used to indicate a position of thefirst subframe of the first radio frame on the first carrier.

With reference to the second possible implementation of the secondaspect, in a third possible implementation manner, before the receivingRRC dedicated signaling sent by the network device, receiving, by theuser equipment, system information sent by the network device, where thesystem information is scheduled by an ePDCCH scrambled by a systeminformation radio network temporary identifier SI-RNTI;

sending, by the user equipment, random access information to the networkdevice, where configuration information of the random access informationis obtained from the system information;

receiving, by the user equipment, random access response informationsent by the network device, where the random access response informationis scheduled by an ePDCCH scrambled by a random access radio networktemporary identifier RA-RNTI; and

receiving, by the user equipment, RRC connection setup information sentby the network device.

According to a third aspect, the present invention further provides anetwork device, which includes:

a determining module, configured to determine a first subframe of afirst radio frame on a first carrier, and transmit a position of thedetermined first subframe to a sending module, where the first subframeincludes a control region, the control region is in first n symbols ofthe first subframe, and n is a natural number less than 5; and

the sending module, configured to send control information in thecontrol region of the first subframe of the first radio frame to a userequipment, and send a demodulation reference signal in the firstsubframe of the first radio frame to the user equipment, where thecontrol information at least includes a PDCCH, where

the sending module is further configured to send an ePDCCH in a secondsubframe of the first radio frame to the user equipment.

With reference to the third aspect, in a first possible implementationmanner, in the sending a demodulation reference signal in the firstsubframe to the user equipment, the demodulation reference signal issent only when the control information is sent; and/or, the demodulationreference signal is only used to demodulate the control information.

With reference to the third aspect, or in the first possibleimplementation of the third aspect, in a second possible implementationmanner, the sending module is further configured to send RRC dedicatedsignaling to the user equipment, so as to indicate a position of thefirst subframe of the first radio frame on the first carrier to the userequipment.

With reference to the second possible implementation of the thirdaspect, in a third possible implementation manner, the network devicefurther includes:

an RRC connection module, configured to: before the radio resourcecontrol RRC dedicated signaling is sent to the user equipment, sendsystem information to the user equipment, where the system informationis scheduled by an ePDCCH scrambled by a system information radionetwork temporary identifier SI-RNTI; receive random access informationsent by the user equipment, where configuration information of therandom access information is obtained from the system information; sendrandom access response information to the user equipment, where therandom access response information is scheduled by an ePDCCH scrambledby a random access radio network temporary identifier RA-RNTI; and sendRRC connection setup information to the user equipment.

According to a fourth aspect, the present invention further provides acontrol information receiving apparatus, which includes:

a determining module, configured to determine a first subframe of afirst radio frame on a first carrier, where the first subframe includesa control region, the control region is in first n symbols of the firstsubframe, and n is a natural number less than 5; and

a receiving module, configured to receive control information, sent by anetwork device, in the control region of the first subframe of the firstradio frame that is determined by the determining module, and receive ademodulation reference signal, sent by the network device, in the firstsubframe, where the control information at least includes a PDCCH, where

the receiving module is further configured to receive an ePDCCH, sent bythe network device, in a second subframe of the first radio frame.

With reference to the fourth aspect, in a first possible implementationmanner, in the receiving a demodulation reference signal, sent by thenetwork device, in the first subframe, the demodulation reference signalis sent only when the control information is sent; and/or, thedemodulation reference signal is only used to demodulate the controlinformation.

With reference to the fourth aspect, or the first possibleimplementation of the fourth aspect, in a second possible implementationmanner, the receiving module is further configured to: before the firstsubframe of the first radio frame on the first carrier is determined,receive RRC dedicated signaling sent by the network device, where theRRC dedicated signaling is used to indicate a position of the firstsubframe of the first radio frame on the first carrier.

With reference to the second possible implementation of the fourthaspect, in a third possible implementation manner, the apparatus furtherincludes: an RRC connection module, configured to: before RRC dedicatedsignaling sent by the network device is received, receive systeminformation sent by the network device, where the system information isscheduled by an ePDCCH scrambled by a system information radio networktemporary identifier SI-RNTI; send random access information to thenetwork device, where configuration information of the random accessinformation is obtained from the system information; receive randomaccess response information sent by the network device, where the randomaccess response information is scheduled by an ePDCCH scrambled by arandom access radio network temporary identifier RA-RNTI; and receiveRRC connection setup information sent by the network device.

In the technical solutions provided in the embodiments of the presentinvention, a first radio frame on a first carrier includes a firstsubframe where a control region is set, and a network device can sendcontrol information borne on a PDCCH to a user equipment through thefirst subframe of the radio frame. Therefore, when control informationborne on an ePDCCH cannot be sent in the radio frame, the PDCCH canstill be sent to the user equipment through the control region in thefirst subframe, thereby achieving purposes of performing uplink/downlinkscheduling for the user equipment and downlink feedback for uplink dataof the user equipment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart of a control information sending method accordingto an embodiment of the present invention;

FIG. 2 is a schematic diagram of a first radio frame on a first carrieraccording to an embodiment of the present invention;

FIG. 3 is a flowchart of a random access method according to anembodiment of the present invention;

FIG. 4 is a flowchart of a control information receiving methodaccording to an embodiment of the present invention;

FIG. 5 is a flowchart of another random access method according to anembodiment of the present invention;

FIG. 6 is a schematic structural diagram of a control informationsending apparatus according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of another control informationsending apparatus according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a control informationreceiving apparatus according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of another control informationreceiving apparatus according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a first subframe on a first carrieraccording to an embodiment of the present invention;

FIG. 11(a) and FIG. 11(b) are schematic diagrams of a control regionaccording to an embodiment of the present invention; and

FIG. 12(a) and FIG. 12(b) are schematic diagrams of another controlregion according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following first describes the concept of a subframe in an LTE systemand channels involved in embodiments of the present invention. In an LTEsystem, one radio frame includes 10 subframes in a time domain, and onecarrier includes multiple resource block pairs (RB pair for short) in afrequency domain. A base station performs scheduling in units of RBpairs. One RB pair occupies one subframe in terms of time and occupies12 orthogonal frequency division multiplexing (OFDM for short)subcarriers in terms of frequency. In the case of a normal cyclicprefix, one subframe includes 14 OFDM symbols; in the case of anextended cyclic prefix, one subframe includes 12 OFDM symbols. A PHICHis downlink acknowledgement/non-acknowledgement information fed back toan uplink PUSCH, and a PCFICH is used to dynamically indicate the numberof symbols occupied by the control region in a current subframe. Datascheduling on a backward compatible carrier is completed by a PDCCH. ThePDCCH is generally sent by using a space-frequency transmit diversitymechanism. The PDCCH includes DL_assignment for scheduling downlink dataPDSCH and UL_grant for scheduling uplink data PUSCH.

FIG. 1 is a flowchart of a control information sending method accordingto an embodiment of the present invention. In this embodiment, theexecuting entity is a network device, for example, it may be an accessnetwork device, such as a base station. As shown in FIG. 1B, the methodprovided in this embodiment includes:

Step 11: The network device determines a first subframe of a first radioframe on a first carrier, where the first subframe includes a controlregion.

The first carrier defined in the embodiment of the present invention maybe a carrier defined in an LTE system later than release 11. The carrierdefined in an LTE system later than release 11 can be called a backwardcompatible carrier. For example, the first carrier does not supportaccess of a UE of an LTE system earlier than release 11. Specifically, asynchronization signal on the first carrier may be modified, so that thesynchronization signal is different from that of the backward compatiblecarrier, and a UE of an earlier LTE release cannot be accessed. The UEof an earlier LTE release may also be prevented, by using anothermethod, from accessing the carrier. For another example, a CRS is sentonly in a part of subframes and/or a part of bandwidths on the firstcarrier. However, a CRS needs to be sent in each subframe on a backwardcompatible carrier, and even though there is no information to be sent,a CRS must also be sent for the UE to perform an operation such asmeasurement. For another example, the first carrier supports aconfiguration of an ePDCCH public search space, while a public searchspace of a backward compatible carrier is located in a public searchspace of a PDCCH in the control region. Definitely, any other differencebetween the first carrier and the backward compatible carrier is notexcluded.

On the first carrier, there may be one radio frame that includes a firstsubframe where a control region is set, and there may also be multipleradio frames that include first subframes. The control region is infirst n symbols of the first subframe, where n is a natural number lessthan 5. The control region may be a control region for time divisionmultiplexing of data.

In the radio frame that includes the first subframe, any other subframeexcept the first subframe is called a second subframe. No control regionis set in a second subframe of the first radio frame. The secondsubframe may be used to send an ePDCCH. In the following, a radio framethat includes the first subframe and the second subframe is called afirst radio frame. The first radio frame may include one or more firstsubframes. Using FIG. 2 as an example, subframe 6 is configured with acontrol region where the number of symbols is 2, and subframe 6 is afirst subframe; subframe 0 has no control region, scheduling for a userequipment depends on the ePDCCH, and subframe 0 is a second subframe.

Step 12: Send control information in the control region of the firstsubframe of the first radio frame to a user equipment, send ademodulation reference signal in the first subframe of the first radioframe to the user equipment, and send an ePDCCH in the second subframeof the first radio frame to the user equipment, where the controlinformation includes a PDCCH or a first ePDCCH.

The network device may send a second ePDCCH in the second subframe ofthe first radio frame to the user equipment.

When the network device sends the control information in the controlregion of the first subframe to the user equipment, the network devicesends the demodulation reference signal in the first subframe to theuser equipment. Optionally, the demodulation reference signal is sentonly when the control information is sent, or the demodulation referencesignal is used for demodulation of the control information in thecontrol region, but is not used for other operations such as measurementor synchronization. Therefore, the demodulation reference signal is notsent when the control information is not sent, so that the networkdevice can save energy, and interference on a neighboring cell can bereduced. Specifically, the UE performs accurate synchronization and/orradio resource management measurement (including measurement onreference signal receiving power, reference signal receiving quality,and the like) by using a CRS that is periodically sent on the firstcarrier, for example, a CRS with a cycle of 5 ms (such as CRSs insubframe 0 and subframe 5). However, assuming that the foregoingdemodulation reference signal in the first subframe can use a resourceposition of the CRS, the demodulation reference signal in the firstsubframe is only used for demodulation, for example, is only used fordemodulation of the control information in the control region, and isnot used for the accurate synchronization and/or radio resourcemanagement measurement.

Optionally, if the network device sends the control information in thecontrol region of the first subframe to the user equipment, the networkdevice also sends the demodulation reference signal in the firstsubframe to the user equipment; and if the network device does not sendthe control information in the control region of the first subframe, thenetwork device does not send the demodulation reference signal in thefirst subframe. This is because the demodulation reference signal isonly used for demodulation of the control information in the controlregion, and is not used for other operations such as measurement orsynchronization. Therefore, the demodulation reference signal is notsent when the control information is not sent, so that the networkdevice can save energy, and interference on a neighboring cell can bereduced.

Optionally, the network device may send the demodulation referencesignal in the control region in the first subframe of the first radioframe to the user equipment. Optionally, a time-frequency positionand/or a sequence of the demodulation reference signal is the same asthat of a cell-specific reference signal CRS defined in an LTE systemearlier than release 11.

Optionally, an antenna port corresponding to the demodulation referencesignal is all or a part of antenna ports 7 to 10 in the LTE system,where the antenna ports 7 to 10 are antenna ports corresponding to auser equipment-specific reference signal.

The network device may further send the ePDCCH in the second subframe ofthe first radio frame to the user equipment. The control information atleast includes a PDCCH. Therefore, the first radio frame may be used tosend the PDCCH and may also be used to send the ePDCCH.

The PDCCH in the control region uses non-precoding transmission and istransmitted by using a single antenna port or a transmit diversitymechanism. The time-frequency position and/or the sequence of thedemodulation reference signal used to demodulate the PDCCH may be thesame as that of a cell-specific reference signal CRS defined in the LTEsystem earlier than release 11; or, the PDCCH may be demodulateddepending on a UERS, where the UERS is all or a part of configurationinformation of a user equipment-specific reference signal UERS ofantenna ports 7 to 10 in an LTE system of release 11. As shown in FIG.10, using a 2-symbol control region as an example, the region includes ahalf of UERS time and frequency resources of an LTE system of theoriginal release Rel-11, that is, a UERS that occupies two symbols, andthe antenna port may also be half of the ports 7 to 10, for example,only antenna ports 7 and 8 or antenna ports 7 and 9 are supported, andcertainly, all of ports 7 to 10 may also be supported. Alternatively,the PDCCH may also use a precoding transmission mode similar to that ofthe ePDCCH; in this case, the demodulation reference signal such as CRSor UERS is precoded together with the PDCCH, and for the CRS, all or apart of CRS ports 0 to 3 may be used. The PDCCH may be uplink schedulegrant (Uplink_grant, UL_grant for short) and may also be downlinkschedule assignment (Downlink_assignment, DL_assignment for short).Further, the control information further includes a PHICH and/or aPCFICH. The UE receives the PDCCH in the first subframe. If the firstsubframe further includes a PHICH and a PCFICH, the UE may furtherreceive the PHICH and the PCFICH. The UE receives only the ePDCCH in thesecond subframe.

The first enhanced physical downlink control channel ePDCCH may also besent in the control region. Generally, the first ePDCCH is transmittedin precoding mode and based on the UERS. Alternatively, the first ePDCCHmay also be transmitted based on the CRS, and in this case, the CRSneeds to be precoded together with the first ePDCCH. Alternatively, thefirst ePDCCH may also be transmitted by using a non-precoding singleantenna port or transmit diversity similar to that of the PDCCH, and inthis case, the demodulation reference signal may be a CRS or a UERS.

In addition, in a current LTE system, a subcarrier shift may beimplemented for a frequency domain position of a CRS in a PRB accordingto a cell identifier, for example, a single-port CRS corresponding tocell identifier 0 is on subcarrier 0 and subcarrier 6 in a certainsymbol of one PRB, a single-port CRS corresponding to cell identifier 1is on subcarrier 1 and subcarrier 7 in a certain symbol of one PRB, andso on. Subcarrier positions of a UERS in a certain symbol of one PRB arefixed, for example, a UERS of ports 7 and 8 occupies subcarriers 0, 5,and 10. Therefore, if the CRS and the UERS in the control regioncoincide, conflict may occur. One solution is to disablecell-identifier-based frequency-domain subcarrier shift of the CRS, andpredefine subcarrier positions that do not conflict with the UERS, forexample, subcarrier 2 and subcarrier 8. Another solution is to enablecell-identifier-based subcarrier shift of the UERS and the CRS. Forexample, the CRS occupies subcarriers 0 and 6, and correspondingly, theUERS changes to subcarriers 1, 6, and 11.

Further, the second ePDCCH may be an ePDCCH introduced in the LTE systemof release 11. The second ePDCCH is assigned in units of PRB pairs andmay be transmitted in precoding mode and based on UE-specific referencesignals. The transmission mode of the first ePDCCH may be the same asthat of the second ePDCCH, that is, both are based on UE-specificreference signals and may be based on precoding transmission. However, aresource of the first ePDCCH can occupy only a resource in the abovecontrol region.

Optionally, before determining the first subframe of the first radioframe on the first carrier, the network device may further send radioresource control (RRC for short) dedicated signaling to the userequipment, so as to indicate a position of the first subframe of thefirst radio frame on the first carrier to the user equipment. Besides,the position of the first subframe of the first radio frame may bepreset in the network device and the user equipment separately.Specifically, one indication manner is: when the network deviceindicates which subframe of the first radio frame is the first subframe,where the first radio frame is any radio frame, a bitmap manner may beused as the specific indication manner. For example, if the first radioframe has 10 subframes, 10 bits are used to indicate the first subframesseparately. This manner is also applicable when the number of subframesof the first radio frame differs. For example, if there are eightsubframes, eight bits are used for indication. Another indication manneris: the network device may indicate a cycle of the first subframe and aposition of the first subframe in the cycle. For example, if the cycleis two radio frames, that is, 20 subframes, and positions of the firstsubframe in this cycle are subframes 0 and 1 of radio frame 0, thepositions are subframes 0 and 1 of radio frames 2, 4, 6, and so on, in anext cycle. This manner is more flexible than the first manner, andbetter matching with PMCH subframes can be implemented because a PMCHhas the largest demand for the first subframe.

Optionally, before the network device sends the first ePDCCH in thecontrol region of the first subframe of the first radio frame to theuser equipment, the method according to this embodiment may furtherinclude:

determining a resource block RB group of the first ePDCCH in the controlregion, where the RB group corresponds to one RB pair, and the RB pairis a resource assignment unit of a physical downlink shared channelPDSCH in the LTE system;

determining a first candidate resource of the first ePDCCH in the RBgroup, where the first candidate resource includes a part of or all ofresources of each RB of at least two RBs, and the at least two RBsbelong to the RB group; and

precoding the first ePDCCH and the demodulation reference signal in theat least two RBs or in the RB group to which the first candidateresource belongs.

Optionally, an antenna port corresponding to the first ePDCCH isdetermined; and for the first ePDCCH and the demodulation referencesignal that are corresponding to a same antenna port, the first ePDCCHand the demodulation reference signal that are corresponding to the sameantenna port are precoded by using a same precoding vector or precodingmatrix. Specifically, the antenna port corresponding to the first ePDCCHmay be determined according to the first candidate resource.Specifically, the antenna port may be determined according to a resourceposition of the first candidate resource, for example, a position of apart of resources in one RB corresponds to antenna port 7, and aposition of another part of resources corresponds to antenna port 8; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element ECCE, and one ECCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

As shown in FIG. 11(a), how to configure one resource set of the firstePDCCH is used as an example. In a case where the number of resourcesets is greater than 1, operations on each resource set are similar. Theresource set includes four PRB binding groups, each PRB binding groupincludes eight PRBs, and each PRB includes two enhanced resource elementgroups (eREG,). In other words, one PRB binding group includes 16 eREGs.It is assumed that four eREGs form one enhanced control channel element(ECCE, Enhanced Control Channel Element), and one first ePDCCH may havedifferent aggregation levels, where the aggregation levels aredetermined according to the number of ECCEs, for example, one firstePDCCH may have four aggregation levels: 1, 2, 4, and 8, which meansthat one first ePDCCH may be formed by 1, 2, 4, or 8 ECCEs. Definitely,similar processing is performed for any other aggregation level. Thefirst ePDCCH also involves a concept of a search space. For firstePDCCHs of different aggregation levels, search spaces corresponding tothe aggregation levels may exist, that is, resource spaces for detectingthe first ePDCCHs. In a search space, there are multiple candidateresources of the first ePDCCH, that is, candidate positions. In otherwords, the first ePDCCH is sent in one or more positions of the multiplecandidate resources, and correspondingly, the UE detects the firstePDCCH only on these candidate resources in the search space. Usingaggregation level 1 as an example, it is assumed that there are fourcandidate resources, and each candidate resource is formed by one ECCE,that is, four eREGs. As shown in FIG. 11(a), eREGs 0, 4, 8, and 12 formECCE 0, eREGs 1, 5, 9, and 13 form ECCE 1, eREGs 2, 6, 10, and 14 formECCE 2, and eREGs 3, 7, 11, and 15 form ECCE 3. Definitely, candidateresources of aggregation level 2 may be ECCEs 0 and 1, ECCEs 2 and 3,and so on. A UERS antenna port used by the first ePDCCH may correspondto the ECCE or eREGs occupied by the first ePDCCH. Using the ECCE as anexample, ECCE 0 may correspond to port 7, ECCE 1 may correspond to port8, ECCE 2 may correspond to port 9, and ECCE 3 may correspond to port10; and definitely, any other similar example is not excluded. Besides,the first ePDCCH and the UERS corresponding to the port need to beprecoded, that is, multiplied by a precoding vector or matrix. Thecandidate resource, ECCE 0, of aggregation level 1 is still used as anexample. Specifically, in the at least two PRBs included in thecandidate resource, that is, PRBs 0, 2, 4, and 6, or in a PRB bindinggroup to which the first candidate resource belongs, that is, PRBs 0 to7, the first ePDCCH and UERS to be sent on the candidate resource may beprecoded for a same antenna port, that is, antenna port 7 correspondingto ECCE 0. To enhance detection performance for the first ePDCCH, thefirst ePDCCH and the UERS may be precoded by using a same precodingvector or precoding matrix. In this way, when the UE receives the firstePDCCH, PRBs 0, 2, 4, and 6 occupied by the candidate resource, or theUERSs in PRBs 0 to 7 in the PRB binding group to which the candidateresource belongs can be used for joint channel estimation, that is,interpolation can be performed, which improves correctness of channelestimation and further improves the detection performance for the firstePDCCH. The above candidate resource is the first candidate resource,and the first ePDCCH transmitted on the first candidate resource may bea centralized ePDCCH and may also be a distributed ePDCCH. In the aboveexample, the centralized ePDCCH is used, that is, a single antenna portis used for precoding. For the distributed ePDCCH, one candidateresource may also be mapped to multiple PRBs, and two antenna ports,such as ports 7 and 9 or ports 7 and 8, may be used alternately toperform random precoding, so as to obtain a diversity gain.

Optionally, before the network device sends the first ePDCCH in thecontrol region of the first subframe of the first radio frame to theuser equipment, the method according to this embodiment may furtherinclude:

determining a resource set of the first ePDCCH in the control region,where the resource set includes multiple resource block RB groups, eachRB group of the multiple RB groups corresponds to one RB pair, and theRB pair is a resource assignment unit of a physical downlink sharedchannel PDSCH in the LTE system;

determining a second candidate resource of the first ePDCCH in theresource set, where the second candidate resource includes a part of orall of resources of each RB group of at least two RB groups, and the atleast two RB groups are RB groups of the multiple RB groups; and

precoding the demodulation reference signal and the first ePDCCH thatare borne in the at least two RB groups included in the second candidateresource.

Further, the network device sends the precoded demodulation referencesignal and first ePDCCH in the control region of the first subframe ofthe first radio frame to the user equipment.

Optionally, an antenna port corresponding to the first ePDCCH isdetermined; and in each RB group included in the second candidateresource, for the first ePDCCH and the demodulation reference signalthat are corresponding to a same antenna port, the first ePDCCH and thedemodulation reference signal that are corresponding to the same antennaport are precoded by using a same precoding vector or precoding matrix.Specifically, the antenna port corresponding to the first ePDCCH may bedetermined according to the second candidate resource. Specifically, theantenna port may be determined according to a resource position of thesecond candidate resource, for example, a position of a part ofresources in one RB corresponds to antenna port 7, and a position ofanother part of resources corresponds to antenna port 8; the antennaport may also be determined according to a resource unit number or aresource position of the first ePDCCH, where the resource unit is atleast one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element ECCE, and one ECCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

As shown in FIG. 11(b), how to configure one resource set of the firstePDCCH is used as an example. In a case where the number of resourcesets is greater than 1, operations on each resource set are similar. Theresource set includes four PRB binding groups, each PRB binding groupincludes eight PRBs, and each PRB includes two eREGs. In other words,one PRB binding group includes 16 eREGs. It is assumed that four eREGsform one ECCE. These basic parameters are the same as those in theforegoing embodiment, and the definition of the search space is also thesame. Still using aggregation level 1 as an example, it is assumed thatthere are four candidate resources, and each candidate resource isformed by one ECCE, that is, four eREGs. As shown in FIG. 11(b), onlythe four eREGs are mapped to different PRB binding groups. For example,eREG 0 in PRB binding group 0, eREG 4 in PRB binding group 1, eREG 8 inPRB binding group 2, and eREG 12 in PRB binding group 3 form ECCE 0, andothers are as shown in FIG. 11(b). Definitely, candidate resources ofaggregation level 2 may be ECCEs 0 and 1, or ECCEs 2 and 3, or the like.In this way, a greater frequency diversity gain can be obtained throughmapping. The UERS antenna port used by the first ePDCCH may correspondto the ECCE, or eREG, or resource element (RE, Resource Element)occupied by the first ePDCCH. For example, in a granularity of REs,different REs in eCCE 0 may alternately correspond to port 7 and port 9,or port 7 and port 8, or the like. Definitely, any other similar exampleis not excluded. Besides, the first ePDCCH and the UERS corresponding tothe port need to be precoded, that is, multiplied by a precoding vectoror matrix. Specifically, the candidate resources eCCEs 0 and 1 ofaggregation level 2 are still used as an example: the occupied resourcesare PRBs 0 and 2 in PRB binding group 0, PRBs 2 and 4 in PRB bindinggroup 1, PRBs 4 and 6 in PRB binding group 0, and PRBs 0 and 6 in PRBbinding group 0. Then, the first ePDCCH and the UERS to be sent on thecandidate resources are precoded for a same antenna port, such as port7. To enhance detection performance for the first ePDCCH, the firstePDCCH and the UERS may be precoded by using a same precoding vector orprecoding matrix. For example, the same precoding vector or matrix isused in the PRBs, occupied by the candidate resource, in each PRBbinding group, such as PRBs 0 and 2 in PRB binding group 0, or in PRBsin another binding group; or, the same precoding vector or matrix isused in all PRBs in each PRB binding group. In this way, when the UEreceives the first ePDCCH, PRBs 0 and 2, occupied by the candidateresource, in the PRB binding group, or the UERSs in PRBs 0 to 7 in PRBbinding group 0 to which the candidate resource belongs, can be used forjoint channel estimation, that is, interpolation can be performed, whichimproves correctness of channel estimation and further improves thedetection performance for the first ePDCCH. The candidate resource isthe second candidate resource, and the first ePDCCH transmitted on thesecond candidate resource is a distributed ePDCCH. For the distributedePDCCH, one candidate resource may be mapped to multiple PRB bindinggroups, and two antenna ports, such as ports 7 and 9 or ports 7 and 8,may be alternately used to perform random precoding, so as to obtain afrequency domain diversity gain and an antenna diversity gain.

Optionally, before the network device sends the first ePDCCH in thecontrol region of the first subframe of the first radio frame to theuser equipment, the method according to this embodiment may furtherinclude:

determining, a third candidate resource bearing the first ePDCCH in thecontrol region, where the third candidate resource includes resources inat least two resource block RBs; and

determining an antenna port corresponding to the first ePDCCH borne onthe third candidate resource.

Specifically, the corresponding antenna port may be determined accordingto a position of the third candidate resource; an antenna port may alsobe randomly selected from a preconfigured antenna port set, for example,the antenna port set includes ports 7 and 8, and the network device mayselect port 8 and then notifies the UE that the port 8 is selected; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specifically, a port may be randomlyselected, and then configured for the UE through the RRC signaling.

If any proper subset of the third candidate resource not capable oftransmitting any complete ePDCCH, or if any two proper subsets of thethird candidate resource are not capable of transmitting any twocomplete ePDCCHs separately by using a same antenna port, in theresources in the at least two RBs, for the first ePDCCH and thedemodulation reference signal that are corresponding to a same antennaport, the first ePDCCH and the demodulation reference signal that arecorresponding to the same antenna port are precoded by using a sameprecoding vector or precoding matrix.

Further, the network device sends the precoded demodulation referencesignal and first ePDCCH in the control region of the first subframe ofthe first radio frame to the user equipment.

Optionally, before the network device sends control information to theuser equipment, the above method may further include:

indicating an antenna port mode to the UE, where the antenna port modeis a single-antenna-port mode in units of enhanced control channelelement eCCEs, or a two-antenna-port mode in units of resource elementREs.

Specifically, because the number of time domain symbols occupied by thecontrol region is small, the number of frequency domain RBs occupied byone ePDCCH candidate resource is greater than the number of frequencydomain RBs occupied by the second ePDCCH. As a result, the centralizedsecond ePDCCH occupies resources in one RB pair in priority. Therefore,the first ePDCCH in the control region can obtain enough frequencydomain diversity gains, and centralized and distributed ePDCCHs can bedistinguished merely by antenna port utilization manners, not byresource mapping manners. For example, one type of the first ePDCCH istransmitted through a single antenna port of a centralized second ePDCCHand based on channel information precoding, and another type of thefirst ePDCCH is transmitted through dual antenna ports of a distributedsecond ePDCCH alternately and based on random precoding. That an antennaport corresponding to the first ePDCCH is determined includes:determining the antenna port corresponding to the first ePDCCHcorresponding to the antenna port mode. Specifically, the antenna portcorresponding to the first ePDCCH is an antenna port used to transmitthe first ePDCCH, so the antenna port corresponding to the first ePDCCHcorresponding to the antenna port mode may be understood as an antennaport used to transmit the first ePDCCH and corresponding to the abovesingle-antenna-port mode or dual antenna port mode.

Specifically, as shown in FIG. 12, it is assumed that one resource setof the first ePDCCH is configured, the set includes 16 PRBs in thecontrol region, each PRB includes two eREGs, and one eCCE includes foureREGs. Certainly, processing is similar in a case where another numberof resource sets are configured, one set includes another number ofPRBs, one PRB includes another number of eREGs, or one eCCE includesanother number of eREGs, which is not limited herein. Using aggregationlevel 1 as an example, as shown in FIG. 12(a), a third candidateresource is eCCE 0, eCCE 1, eCCE 2, or eCCE 3, and corresponding antennaports are ports 7, 8, 9, and 10, separately; for aggregation level 2, anexample in which third candidate resources are eCCEs 4 and 5 is used,and corresponding antenna port is port 7 or 8, which may specifically beconfigured by using high layer signaling or determined by using a UEidentifier; for aggregation level 4, an example in which third candidateresources are eCCEs 4, 5, 6, and 7 is used, and a specific antenna portmay be predefined and may also be configured by using high layersignaling or determined by using a UE identifier. The first ePDCCH borneon the third candidate resource is a centralized ePDCCH. An example inFIG. 12(b) is similar. It can be seen that a centralized first ePDCCH,especially that of a low aggregation level, such as aggregation level 1,may occupy resources in multiple PRBs, so that frequency diversity andfrequency selective gains can be increased.

Besides, if a part of the third candidate resources cannot be used totransmit another first ePDCCH, using a third candidate resource ofaggregation level 1 in FIG. 12(a) or FIG. 12(b), eCCE 0 as an example,it can be seen that a part of resources where eCCE 0 is located cannotbe used as another third candidate resource, then, in the at least twoPRBs included in the third candidate resource, such as PRBs 0 to 3included in eCCE 0 shown in FIG. 12(a) or PRBs 0 and 1 in eCCE 0 shownin FIG. 12(b), the first ePDCCH may be precoded by using a sameprecoding vector or precoding matrix, for a same antenna port, such asantenna port 7 used to transmit eCCE 0; in other words, the first ePDCCHis precoded by using the same precoding vector or matrix betweenmultiple PRBs occupied by eCCE 0. Alternatively, if any first part ofresources and second part of resources of the third resources cannot beused to transmit another two first ePDCCHs by using a same antenna port,for example, using eCCEs 4 and 5 of aggregation level 2 in FIG. 12(a) asan example, the third candidate resources may have two parts that areseparately used as other third candidate resources, that is, eCCE 4 asone part, and eCCE 5 as the other part, which are used as thirdcandidate resources of aggregation level 1, but the third candidateresources of the two parts cannot be simultaneously transmitted by usinga same antenna port because PRBs occupied by them are overlapped, then,in the at least two PRBs included in the above third candidateresources, such as PRBs 8 to 11, the first ePDCCH may be precoded byusing a same precoding vector or precoding matrix, for the same antennaport, such as antenna port 7 used for the first ePDCCH transmitted onthe third candidate resources of aggregation level 2; in other words,the first ePDCCH is precoded by using the same precoding vector ormatrix between multiple PRBs occupied by eCCEs 4 and 5. However, for thethird candidate resources of aggregation level 4 in FIG. 12(a), such aseCCEs 4, 5, 6, and 7, assuming that one part of the resources includeseCCEs 4 and 5 of aggregation level 2, and the other part includes eCCEs6 and 7 of aggregation level 2, the third candidate resources of the twoparts may simultaneously transmit the first ePDCCH by using a sameantenna port because the PRBs of the two parts are not overlapped.Therefore, generally, the first ePDCCH transmitted on the thirdcandidate resources of aggregation level 4 cannot be precoded by using asame precoding vector or matrix between the occupied eight PRBs, but thetwo parts of the third candidate resources of aggregation level 4 canperform precoding separately by using a same precoding vector or matrix.Similarly, eCCEs 4 and eCCE 5 of aggregation level 2 in FIG. 12(b)cannot use a same precoding vector or matrix between PRBs 8 to 11, butcan use a same precoding vector or matrix only for PRBs 8 and 9 or forPRBs 10 and 11 to implement precoding.

In addition, it can also be seen that the third candidate resource mayoccupy resources on multiple PRBs. Therefore, the mapping manner of thecentralized first ePDCCH may also be used by the distributed firstePDCCH, that is, the mapping manners of the centralized first ePDCCH andthe distributed first ePDCCH are the same because a diversity gainbetween multiple PRBs over a frequency can be obtained. However, antennaport modes are different. For example, the centralized ePDCCH generallyuses one antenna port, and the port may correspond to an eCCE, while thedistributed ePDCCH generally uses two ports, and the two ports arealternately used in a granularity of REs or REGs to achieve an effect ofan antenna domain diversity. Then, for the first ePDCCH that transmitstwo antenna port determination manners in the same resource mappingmanner, the network device needs to indicate the antenna port mode tothe UE, where the antenna port mode is an antenna port mode for thecentralized or distributed resource mapping manner in an existingsystem. Specifically, radio resource control signaling, or Layer 1/2signaling such as physical layer signaling or media access layersignaling, may be used.

In the technical solutions provided in this embodiment, a first radioframe on a first carrier includes a first subframe where a controlregion is set, and a network device can send a PDCCH to a user equipmentthrough the first subframe of the first radio frame. Therefore, when anePDCCH cannot be sent in the first radio frame, the PDCCH can still besent to the user equipment through the control region in the firstsubframe, thereby achieving purposes of performing uplink/downlinkscheduling for the user equipment and downlink feedback for uplink dataof the user equipment.

For example, the first subframe is one or more types of the followingsubframes: a multimedia broadcast multicast service single frequencynetwork (MBSFN for short) subframe, a subframe bearing a channel stateinformation reference signal (CSI-RS for short), special subframes inTDD special subframe configurations 0 and 5, and a physical multicastchannel (PMCH for short) subframe. Alternatively, if a broadcast messageis not configured with an MBSFN subframe, the network device does notconfigure the first subframe, that is, the network device only sends thesecond ePDCCH; and if a broadcast message is configured with an MBSFNsubframe, the network device can configure the first subframe and sendthe PDCCH or the first ePDCCH.

Using the MBSFN subframe as an example, if a radio frame of a carrier isconfigured with an MBSFN subframe, where a multimedia broadcastmulticast service (Multimedia Broadcast Multicast Service, MBMS forshort) is transmitted in the subframe, and the MBMS service occupies allcarrier bandwidths in the MBSFN subframe, a control region and ademodulation region can be set in other subframes in the radio frameexcept the MBSFN subframe, and the control information borne in thePDCCH, including UL_grant, is sent in the subframe set with the controlregion and the demodulation region, that is, the first subframe, to theuser equipment, thereby implementing uplink scheduling and downlinkscheduling for the user equipment.

Using a subframe bearing a CSI-RS as an example, the CSI-RS is used forchannel state information measurement and is configured for the userequipment only after setup of an RRC connection is completed. The UEdoes not know the CSI-RS configuration on the current carrier duringaccess to the LTE system. The control region is set in a subframe exceptthe subframe bearing the CSI-RS, that is, the first subframe, the CSI-RSis sent in the subframe bearing the CSI-RS, and scheduling informationof public control information that is originally borne on an ePDCCH inan ePDCCH public search space, such as scheduling information of systeminformation blocks, paging, and random access response, is sent in thefirst subframe. Because the control region is not overlapped with theCSI-RS resource, an impact on CSI-RS measurement can be avoided. If thescheduling information of the public control information is borne in theePDCCH sent through the ePDCCH public search space in the CSI-RSsubframe, the following problem may occur: The base station sends thescheduling information of the public control information in the ePDCCHpublic search space in the CSI-RS subframe; for a user equipment thatneeds to receive the scheduling information of the public controlinformation, it is assumed that the CSI-RS does not exist, while for auser equipment that does not need to receive the scheduling informationof the public control information and a user equipment that needs toreceive the CSI-RS in the ePDCCH public search space to implementchannel measurement or interference measurement, there is no CSI-RS,which affects CSI-RS measurement considerably, for example, informationthat is not CSI-RS information is treated as CSI-RS information and usedfor measurement, causing a great error in a measurement result.

Using special subframes in TDD special subframe configurations 0 and 5as an example, DwPTS in these special subframes has only three symbolsand is not suitable for ePDCCH transmission, and these special subframescannot bear the UL_grant and PHICH. A control region and a demodulationregion can be set in other subframes in TDD special subframeconfigurations 0 and 5, so as to send the UL_grant and PHICH.

Optionally, before the control information is sent in the control regionof the first subframe of the first radio frame, the method furtherincludes: notifying, by the network device, the user equipment of aposition of the control region, where the first subframe includesmultiple control regions, and the multiple control regions arefrequency-multiplexed. Specifically, one or more of the multiple controlregions may be configured for the UE. If one control region isconfigured for the UE, the UE detects the control information, such asPDCCH, in the configured control region; if multiple control regions areconfigured for the UE, the UE detects the control information, such asPDCCH, in the configured multiple control regions. In this case, inorder to ensure that the number of PDCCH blind detections does notincrease, the current number of blind detections of the UE needs to bedistributed to the configured multiple control regions. The specificmethod is distributing the number of blind detections according to acontrol channel format, or evenly distributing the number of blinddetections of a same control channel format to the configured multiplecontrol regions.

Optionally, in order to implement inter-cell interference coordination,the control information and/or the demodulation signal is sent over apart of bandwidths of the first carrier. If the PDCCH sent in thecontrol region is interleaved and distributed to all the bandwidths, itis disadvantageous for inter-cell interference coordination. This is thesame case for the PHICH and PCFICH. The control region may be located ina part of bandwidths of the carrier. For example, a carrier bandwidth is20 MHz, a control region of cell 1 may be configured at a bandwidth of10 MHz, and a control region of cell 2 may be configured at anotherbandwidth of 10 MHz, so as to implement inter-cell interferencecoordination. In addition, for a UE with a small bandwidth receivingcapability, for example, a UE of machine type has only a bandwidthreceiving capability of 3 MHz (certainly, another small bandwidth is notexcluded), the control region may be configured at a certain 3 MHz on anew carrier, and multiple control regions of 3 MHz may also beconfigured to support more UEs of this type, so as to increase controlchannel capacity.

Optionally, the PDCCH in the control region of the first subframe isscrambled or interleaved according to a virtual cell identifier. Ifscrambling and interleaving are implemented according to a cellidentifier, when cell identifiers of different cells are different,interference exists between PDCCHs of the cells. Therefore, the PDCCH inthe control region may be scrambled and interleaved by using a virtualcell identifier. For cells with different cell identifiers, PDCCHs maybe scrambled and interleaved by using a same virtual cell identifier,thereby implementing joint PDCCH receiving to improve performance.

FIG. 3 is a flowchart of a random access method according to anembodiment of the present invention. Based on the above first carrier,this embodiment provides a random access method, including:

Step 31: A network device sends system information to a UE, where thesystem information is scheduled by an ePDCCH scrambled by a systeminformation radio network temporary identifier SI-RNTI.

The network device schedules, through the ePDCCH scrambled by the systeminformation radio network temporary identifier (SI-RNTI for short) andsent in an ePDCCH public search space, the system information sent tothe user equipment. The user equipment detects a synchronization signal,so as to implement synchronization with the first carrier. Aftersynchronization with the first carrier is implemented, the userequipment reads the system information through the ePDCCH scrambled bythe SI-RNTI scrambled and sent in the ePDCCH public search space.

Step 32: The network device receives random access information sent bythe user equipment, where configuration information of the random accessinformation is obtained from the system information.

Step 33: The network device sends random access response information tothe UE, where the random access response information is scheduled by anePDCCH scrambled by an RA-RNTI.

The network device schedules, through the ePDCCH scrambled by the randomaccess radio network temporary identifier (RA-RNTI for short) and sentin an ePDCCH public search space, the random access response informationsent to the user equipment.

Step 34: The network device sends RRC connection setup information tothe UE.

After the user equipment sets up an RRC connection with the networkdevice through the RRC connection setup information sent by the networkdevice, the user equipment can obtain a configuration of the first radioframe on the first carrier, thereby obtaining a configuration of thePDCCH in the first subframe.

In this embodiment, the user equipment first accesses the ePDCCH, andafter the RRC connection is set up, obtains a position of the PDCCH, soas to obtain a configuration of the CSI-RS.

In this embodiment, a user equipment accesses a first carrier of an LTEsystem through an ePDCCH mechanism. An inter-cell interferencecoordination effect of an ePDCCH achieves better access performance incomparison with the previous PDCCH mechanism. After the UE accesses, anetwork device configures a first subframe for the UE, that is, asubframe bearing a control region, so that data scheduling and feedbackcan still be implemented on the first subframe in which the ePDCCHcannot be sent or is sent at a low efficiency.

FIG. 4 is a flowchart of a control information receiving methodaccording to an embodiment of the present invention. As shown in FIG. 4,the method provided in this embodiment includes:

Step 41: A user equipment determines a first subframe in a first radioframe on a first carrier, where the first subframe includes a controlregion, the control region is in first n symbols of the first subframe,and n is a natural number less than 5.

Definitions of the first carrier and the first radio frame are the sameas the definitions in the embodiment corresponding to FIG. 1, anddetails are not repeated herein.

Optionally, before the user equipment receives the control informationin the control region in the first subframe of the first radio frame,the method further includes: obtaining, by the user equipment, aposition of the control region, where the first subframe includesmultiple control regions, and the multiple control regions arefrequency-multiplexed. Specifically, one or more of the multiple controlregions may be configured for the UE. If one control region isconfigured for the UE, the UE detects the control information, such asPDCCH, in the configured control region; if multiple control regions areconfigured for the UE, the UE detects the control information, such asPDCCH, in the configured multiple control regions. In this case, inorder to ensure that the number of PDCCH blind detections does notincrease, the current number of blind detections of the UE needs to bedistributed to the configured multiple control regions. The specificmethod is distributing the number of blind detections according to acontrol channel format, or evenly distributing the number of blinddetections of a same control channel format to the configured multiplecontrol regions.

Step 42: The user equipment receives control information, sent by thenetwork device, in the control region of the first subframe of the firstradio frame, receives a demodulation reference signal, sent by thenetwork device, in the first subframe, where the control information atleast includes a PDCCH or a first enhanced physical downlink controlchannel ePDCCH, and receives the ePDCCH, sent by the network device, ina second subframe of the first radio frame.

The user equipment may receive the PDCCH in the first subframe of thefirst radio frame, and receives the ePDCCH, sent by the network device,in the second subframe of the first radio frame.

Further, the network device sends demodulation information in the firstsubframe to the user equipment only when the control information issent. Alternatively, the demodulation reference signal is only used forcontrol information demodulation, and is not used for operations such assynchronization or measurement. Specifically, the UE performs accuratesynchronization and/or radio resource management measurement (includingmeasurement on reference signal receiving power, reference signalreceiving quality, and the like) by using a CRS that is periodicallysent on the first carrier, for example, a CRS with a cycle of 5 ms (suchas CRSs in subframe 0 and subframe 5). However, assuming that theforegoing demodulation reference signal in the first subframe can use aresource position of the CRS, the demodulation reference signal in thefirst subframe is only used for demodulation, for example, is only usedfor demodulation of the control information in the control region, andis not used for the accurate synchronization and/or radio resourcemanagement measurement.

Optionally, the control information further includes a PHICH and/or aPCFICH.

Optionally, the control information and/or the demodulation referencesignal is sent in a part of bandwidths of the first carrier.

Optionally, a time-frequency position and/or a sequence of thedemodulation reference signal is the same as that of a cell-specificreference signal CRS defined in an LTE system earlier than release 11;or

optionally, an antenna port corresponding to the demodulation referencesignal is all or a part of antenna ports 7 to 10 in the LTE system,where the antenna ports 7 to 10 are antenna ports corresponding to auser equipment-specific reference signal.

Optionally, the receiving a demodulation reference signal, sent by thenetwork device, in the first subframe of the first radio framespecifically is: receiving, by the user equipment, the demodulationreference signal, sent by the network device, in the control region ofthe first subframe of the first radio frame.

Optionally, before step 41, the user equipment may receive RRC dedicatedsignaling sent by the network device. Through the RRC dedicatedsignaling, the user equipment can obtain a position of the firstsubframe of the first radio frame on the first carrier. Specifically,one obtaining manner is: obtaining from the network device whichsubframe of the first radio frame is the first subframe, where the firstradio frame is any radio frame, a bitmap manner may be used as thespecific obtaining manner. For example, if the first radio frame has 10subframes, 10 bits are used to indicate the first subframes separately.This manner is also applicable when the number of subframes of the firstradio frame differs. For example, if there are eight subframes, eightbits are used for indication. Another obtaining manner is: obtainingfrom a cycle of the first subframe and a position of the first subframein the cycle that are indicated by the network device. For example, ifthe cycle is two radio frames, that is, 20 subframes, and positions ofthe first subframe in this cycle are subframes 0 and 1 of radio frame 0,the positions are subframes 0 and 1 of radio frames 2, 4, 6, and so on,in a next cycle. This manner is more flexible than the first manner, andbetter matching with PMCH subframes can be implemented because a PMCHhas the largest demand for the first subframe.

Optionally, the PDCCH in the control region is scrambled or interleavedaccording to a virtual cell identifier. Correspondingly, the userequipment descrambles or de-interleaves the PDCCH in the control regionby using the virtual cell identifier.

Optionally, before the user equipment receives the first ePDCCH, sent bythe network device, in the control region of the first subframe of thefirst radio frame, the method according to this embodiment may furtherinclude:

determining a resource block RB group of the first ePDCCH in the controlregion, where the RB group corresponds to one RB pair, and the RB pairis a resource assignment unit of a physical downlink shared channelPDSCH in the LTE system; and

determining a first candidate resource of the first ePDCCH in the RBgroup, where the first candidate resource includes a part of or all ofresources of each RB of at least two RBs, and the at least two RBsbelong to the RB group; where

the receiving, by the user equipment, the first ePDCCH sent by thenetwork device, in the control region of the first subframe of the firstradio frame includes: receiving the first ePDCCH in the at least two RBsor in the RB group to which the first candidate resource belongs.

Optionally, an antenna port corresponding to the first ePDCCH isdetermined; and on the antenna port corresponding to the first ePDCCH,for the first ePDCCH and the demodulation reference signal that arecorresponding to a same antenna port, it is assumed that a sameprecoding vector or precoding matrix is used to receive the firstePDCCH. Specifically, the antenna port corresponding to the first ePDCCHmay be determined according to the first candidate resource.Specifically, the antenna port may be determined according to a resourceposition of the first candidate resource, for example, a position of apart of resources in one RB corresponds to antenna port 7, and aposition of another part of resources corresponds to antenna port 8; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, before the user equipment receives the first ePDCCH, sent bythe network device, in the control region of the first subframe of thefirst radio frame, the method may further include:

determining a resource set of the first ePDCCH in the control region,where the resource set includes multiple resource block RB groups, eachRB group of the multiple RB groups corresponds to one RB pair, and theRB pair is a resource assignment unit of a physical downlink sharedchannel PDSCH in the LTE system; and

determining a second candidate resource of the first ePDCCH in theresource set, where the second candidate resource includes a part of orall of resources of each RB group of at least two RB groups, and the atleast two RB groups are RB groups of the multiple RB groups; where

the receiving, by the user equipment, the first ePDCCH sent by thenetwork device, in the control region of the first subframe of the firstradio frame includes: receiving the first ePDCCH in the at least two PRBbinding groups included in the second candidate resource.

Optionally, an antenna port corresponding to the first ePDCCH isdetermined; and in each RB group included in the second candidateresource, for the first ePDCCH and the demodulation reference signalthat are corresponding to the same antenna port, it is assumed that asame precoding vector or precoding matrix is used to receive the firstePDCCH. Specifically, the antenna port corresponding to the first ePDCCHmay be determined according to the second candidate resource.Specifically, the antenna port may be determined according to a resourceposition of the second candidate resource, for example, a position of apart of resources in one RB corresponds to antenna port 7, and aposition of another part of resources corresponds to antenna port 8; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, before the user equipment receives the first ePDCCH, sent bythe network device, in the control region of the first subframe of thefirst radio frame, the method may further include:

determining a third candidate resource bearing the first ePDCCH in thecontrol region, where the third candidate resource includes resources inat least two resource block RBs; and

determining an antenna port corresponding to the first ePDCCH borne onthe third candidate resource. Specifically, the antenna portcorresponding to the first ePDCCH may be determined according to thethird candidate resource. Specifically, the antenna port may bedetermined according to a resource position of the third candidateresource, for example, a position of a part of resources in one RBcorresponds to antenna port 7, and a position of another part ofresources corresponds to antenna port 8; the antenna port may also bedetermined according to a resource unit number or a resource position ofthe first ePDCCH, where the resource unit is at least one of an RB pair,an RB, an ECCE, an eREG, and an RE that form the first ePDCCH; and theantenna port may also be configured through RRC dedicated signaling, andspecially, a port may be randomly selected, and then configured for theUE through the RRC signaling.

The receiving, by the user equipment, the first ePDCCH sent by thenetwork device, in the control region of the first subframe of the firstradio frame includes: if any proper subset of the third candidateresource not capable of transmitting any complete ePDCCH, or if any twoproper subsets of the third candidate resource are not capable oftransmitting any two complete ePDCCHs separately by using a same antennaport, in the resources in the at least two RBs, for the first ePDCCH andthe demodulation reference signal that are corresponding to a sameantenna port, receiving the first ePDCCH by using a same precodingvector or precoding matrix.

Optionally, an antenna port mode is obtained from the network device,where the antenna port mode is a single-antenna-port mode in units ofenhanced control channel element eCCEs, or a two-antenna-port mode inunits of resource element REs. Specifically, the antenna portcorresponding to the first ePDCCH is an antenna port used to transmitthe first ePDCCH, so the antenna port corresponding to the first ePDCCHcorresponding to the antenna port mode may be understood as an antennaport used to transmit the first ePDCCH and corresponding to the abovesingle-antenna-port mode or dual antenna port mode.

For specific descriptions, refer to the embodiment of the method at thenetwork side, and details are not repeated herein.

Optionally, before the UE receives the control information, sent by thenetwork device, in the control region of the first subframe of the firstradio frame, the network device notifies the UE of a position of thecontrol region, where the first subframe includes multiple controlregions, and the multiple control regions are frequency-multiplexed.

For example, the first subframe is one or more types of the followingsubframes: an MBSFN subframe, a subframe bearing a CSI-RS, specialsubframes in TDD special subframe configurations 0 and 5, and a physicalmulticast channel subframe. Alternatively, if a broadcast message is notconfigured with an MBSFN subframe, the UE receives only the secondePDCCH; and if a broadcast message is configured with an MBSFN subframe,the network device may obtain the first subframe and receive the PDCCHor the first ePDCCH in the first subframe.

FIG. 5 is a flowchart of another random access method according to anembodiment of the present invention. As shown in FIG. 5, before RRCdedicated signaling sent by a network device is received, thisembodiment further provides the following method.

Step 51: A user equipment receives system information sent by thenetwork device, where the system information is scheduled by an ePDCCHscrambled by a system information radio network temporary identifierSI-RNTI.

Step 52: The user equipment sends random access information to thenetwork device, where configuration information of the random accessinformation is obtained from the system information.

Step 53: The user equipment receives random access response informationsent by the network device, where the random access response informationis scheduled by an ePDCCH scrambled by an RA-RNTI.

Step 54: The user equipment receives RRC connection setup informationsent by the network device.

In this embodiment, a user equipment accesses a first carrier of an LTEsystem through an ePDCCH mechanism. An inter-cell interferencecoordination effect of an ePDCCH achieves better access performance incomparison with the previous PDCCH mechanism. After the UE accesses theLTE system through the ePDCCH mechanism, the UE can obtain a firstsubframe configuration of a network device, that is, a subframe bearinga control region, so that data scheduling and feedback can still beimplemented on the first subframe in which the ePDCCH cannot be sent oris sent at a low efficiency.

FIG. 6 is a schematic structural diagram of a network device accordingto an embodiment of the present invention. As shown in FIG. 6, thenetwork device provided in this embodiment includes: a determiningmodule 61 and a sending module 62.

The determining module 61 is configured to determine a first subframe ofa first radio frame on a first carrier, and transmit a position of thedetermined first subframe to the sending module 62, where the firstsubframe includes a control region, the control region is in first nsymbols of the first subframe, and n is a natural number less than 5.

The sending module 62 is configured to send control information in thecontrol region of the first subframe of the first radio frame to a userequipment, and send a demodulation reference signal in the firstsubframe of the first radio frame to the user equipment, where thecontrol information at least includes a PDCCH or a first ePDCCH.Further, the control information may further include a PHICH and/or aPCFICH.

Optionally, in the sending a demodulation reference signal in the firstsubframe to the user equipment, the demodulation reference signal issent only when the control information is sent; and/or, the demodulationreference signal is only used to demodulate the control information.Specifically, the UE performs accurate synchronization and/or radioresource management measurement (including measurement on referencesignal receiving power, reference signal receiving quality, and thelike) by using a CRS that is periodically sent on the first carrier, forexample, a CRS with a cycle of 5 ms (such as CRSs in subframe 0 andsubframe 5). However, assuming that the foregoing demodulation referencesignal in the first subframe can use a resource position of the CRS, thedemodulation reference signal in the first subframe is only used fordemodulation, for example, is only used for demodulation of the controlinformation in the control region, and is not used for the accuratesynchronization and/or radio resource management measurement.

Optionally, a time-frequency position and/or a sequence of thedemodulation reference signal is the same as that of a cell-specificreference signal CRS defined in an LTE system earlier than release 11.

Optionally, an antenna port corresponding to the demodulation referencesignal is all or a part of antenna ports 7 to 10 in the LTE system,where the antenna ports 7 to 10 are antenna ports corresponding to auser equipment-specific reference signal.

Optionally, the control information and/or the demodulation referencesignal is sent in a part of bandwidths of the first carrier.

Optionally, the sending module is further configured to: before sendingthe control information in the control region of the first subframe ofthe first radio frame to the user equipment, scramble or interleave thePDCCH in the control region by using a virtual cell identifier.

Optionally, the network device provided in this embodiment may furtherinclude a precoding module, where:

the determining module is further configured to: before the sendingmodule sends the first ePDCCH, determine a resource block RB group ofthe first ePDCCH in the control region, where the RB group correspondsto one RB pair, and the RB pair is a resource assignment unit of aphysical downlink shared channel PDSCH in the LTE system, and determinea first candidate resource of the first ePDCCH in the RB group, wherethe first candidate resource includes a part of or all of resources ofeach RB of at least two RBs, and the at least two RBs belong to the RBgroup;

the precoding module is configured to precode the first ePDCCH and thedemodulation reference signal in the at least two RBs determined by thedetermining module or in the RB group to which the first candidateresource determined by the determining module belongs; and

the sending module is specifically configured to send the first ePDCCHand the demodulation reference signal that are precoded by the precodingmodule to the user equipment.

Optionally, the precoding module is specifically configured to precodethe first ePDCCH and the demodulation reference signal in the followingmanner: determining an antenna port corresponding to the first ePDCCH;and for the first ePDCCH and the demodulation reference signal that arecorresponding to a same antenna port, precoding, by using a sameprecoding vector or precoding matrix, the first ePDCCH and thedemodulation reference signal that are corresponding to the same antennaport. Specifically, the antenna port corresponding to the first ePDCCHmay be determined according to the first candidate resource.Specifically, the antenna port may be determined according to a resourceposition of the first candidate resource, for example, a position of apart of resources in one RB corresponds to antenna port 7, and aposition of another part of resources corresponds to antenna port 8; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, the determining module is further configured to: before thesending module sends the first ePDCCH in the control region of the firstsubframe of the first radio frame to the user equipment, determine aresource set of the first ePDCCH in the control region, where theresource set includes multiple resource block RB groups, each RB groupof the multiple RB groups corresponds to one RB pair, and the RB pair isa resource assignment unit of a physical downlink shared channel PDSCHin the LTE system; and

determine a second candidate resource of the first ePDCCH in theresource set, where the second candidate resource includes a part of orall of resources of each RB group of at least two RB groups, and the atleast two RB groups are RB groups of the multiple RB groups;

the precoding module is configured to precode the demodulation referencesignal and the first ePDCCH, where the demodulation reference signal andthe first ePDCCH are precoded and are borne in the at least two RBgroups included in the second candidate resource determined by thedetermining module; and

the sending module is specifically configured to send the first ePDCCHand the demodulation reference signal that are precoded by the precodingmodule to the user equipment.

Optionally, the precoding module is specifically configured to precodethe first ePDCCH and the demodulation reference signal in the followingmanner: determining an antenna port corresponding to the first ePDCCH;and in each RB group included in the second candidate resource, for thefirst ePDCCH and the demodulation reference signal that arecorresponding to a same antenna port, precoding, by using a sameprecoding vector or precoding matrix, the first ePDCCH and thedemodulation reference signal that are corresponding to the same antennaport. Specifically, the antenna port corresponding to the first ePDCCHmay be determined according to the second candidate resource.Specifically, the antenna port may be determined according to a resourceposition of the second candidate resource, for example, a position of apart of resources in one RB corresponds to antenna port 7, and aposition of another part of resources corresponds to antenna port 8; theantenna port may also be determined according to a resource unit numberor a resource position of the first ePDCCH, where the resource unit isat least one of an RB pair, an RB, an ECCE, an eREG, and an RE that formthe first ePDCCH; and the antenna port may also be configured throughRRC dedicated signaling, and specially, a port may be randomly selected,and then configured for the UE through the RRC signaling.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, the determining module is further configured to: before thesending module sends the first ePDCCH in the control region of the firstsubframe of the first radio frame to the user equipment, determine athird candidate resource bearing the first ePDCCH in the control region,where the third candidate resource includes resources in at least tworesource block RBs; and determine an antenna port corresponding to thefirst ePDCCH borne on the third candidate resource. Specifically, theantenna port corresponding to the first ePDCCH may be determinedaccording to the third candidate resource. Specifically, the antennaport may be determined according to a resource position of the thirdcandidate resource, for example, a position of a part of resources inone RB corresponds to antenna port 7, and a position of another part ofresources corresponds to antenna port 8; the antenna port may also bedetermined according to a resource unit number or a resource position ofthe first ePDCCH, where the resource unit is at least one of an RB pair,an RB, an ECCE, an eREG, and an RE that form the first ePDCCH; and theantenna port may also be configured through RRC dedicated signaling, andspecially, a port may be randomly selected, and then configured for theUE through the RRC signaling.

The precoding module is configured to: if any proper subset of the thirdcandidate resource not capable of transmitting any complete ePDCCH, orif any two proper subsets of the third candidate resource are notcapable of transmitting any two complete ePDCCHs separately by using asame antenna port, in the resources in the at least two RBs, for thefirst ePDCCH and the demodulation reference signal that arecorresponding to a same antenna port, precode, by using a same precodingvector or precoding matrix, the first ePDCCH and the demodulationreference signal that are corresponding to the same antenna port; and

the sending module is specifically configured to send the first ePDCCHand the demodulation reference signal that are precoded by the precodingmodule to the user equipment.

Optionally, the sending module is further configured to: before sendingthe control information to the user equipment, indicate an antenna portmode to the user equipment, where the antenna port mode is asingle-antenna-port mode in units of enhanced control channel elementeCCEs, or a two-antenna-port mode in units of resource element REs.Specifically, the antenna port corresponding to the first ePDCCH is anantenna port used to transmit the first ePDCCH, so the antenna portcorresponding to the first ePDCCH corresponding to the antenna port modemay be understood as an antenna port used to transmit the first ePDCCHand corresponding to the above single-antenna-port mode or dual antennaport mode.

Optionally, the sending module 62 is further configured to send a secondePDCCH in a second subframe of the first radio frame to the userequipment.

Optionally, the sending module 62 is further configured to send RRCdedicated signaling to the user equipment, so as to indicate a positionof the first subframe of the first radio frame on the first carrier tothe user equipment. Specifically, one indication manner is: when thenetwork device indicates which subframe of the first radio frame is thefirst subframe, where the first radio frame is any radio frame, a bitmapmanner may be used as the specific indication manner. For example, ifthe first radio frame has 10 subframes, 10 bits are used to indicate thefirst subframes separately. This manner is also applicable when thenumber of subframes of the first radio frame differs. For example, ifthere are eight subframes, eight bits are used for indication. Anotherindication manner is: the network device may indicate a cycle of thefirst subframe and a position of the first subframe in the cycle. Forexample, if the cycle is two radio frames, that is, 20 subframes, andpositions of the first subframe in this cycle are subframes 0 and 1 ofradio frame 0, the positions are subframes 0 and 1 of radio frames 2, 4,6, and so on, in a next cycle. This manner is more flexible than thefirst manner, and better matching with PMCH subframes can be implementedbecause a PMCH has the largest demand for the first subframe.

Optionally, the sending module 62 is further configured to send thedemodulation reference signal in the control region in the firstsubframe of the first radio frame to the user equipment.

Optionally, the sending module 62 is further configured to: beforesending the control information in the control region of the firstsubframe of the first radio frame to the user equipment, notify the userequipment of a position of the control region, where the first subframeincludes multiple control regions, and the multiple control regions arefrequency-multiplexed.

For example, the first subframe is one or more types of the followingsubframes: an MBSFN subframe, a subframe bearing a CSI-RS, specialsubframes in TDD special subframe configurations 0 and 5, and a physicalmulticast channel subframe. Alternatively, if a broadcast message is notconfigured with an MBSFN subframe, the network device does not configurethe first subframe, that is, the network device only sends the secondePDCCH; and if a broadcast message is configured with an MBSFN subframe,the network device can configure the first subframe and send the PDCCHor the first ePDCCH.

The functions of the above modules are described in the embodimentcorresponding to FIG. 1, and details are not repeated herein.

As shown in FIG. 7, the network device provided in this embodiment mayfurther include an RRC connection module 63.

The RRC connection module 63 is configured to: before the sending module62 sends the RRC dedicated signaling to the user equipment, send systeminformation to the user equipment, where the system information isscheduled by an ePDCCH scrambled by a system information radio networktemporary identifier SI-RNTI; receive random access information sent bythe user equipment, where configuration information of the random accessinformation is obtained from the system information; send random accessresponse information to the user equipment, where the random accessresponse information is scheduled by an ePDCCH scrambled by an RA-RNTI;and send RRC connection setup information to the user equipment.

The functions of the above modules are described in the embodimentcorresponding to FIG. 3, and details are not repeated herein.

FIG. 8 is a schematic structural diagram of a control informationreceiving apparatus according to an embodiment of the present invention.As shown in FIG. 8, the apparatus provided in this embodiment includes:a determining module 81 and a receiving module 82.

The determining module 81 is configured to determine at least one firstsubframe of a first radio frame on a first carrier, where the firstsubframe includes a control region, the control region is in first nsymbols of the first subframe, and n is a natural number less than 5.

The receiving module 82 is configured to receive control information,sent by a network device, in the control region of the first subframe ofthe first radio frame that is determined by the determining module 81,and receive a demodulation reference signal, sent by the network device,in the first subframe, where the control information includes a PDCCH ora first ePDCCH. Further, the control information may further include aPHICH and/or a PCFICH.

Optionally, in the receiving a demodulation reference signal, sent bythe network device, in the first subframe, the demodulation referencesignal is sent only when the control information is sent; and/or, thedemodulation reference signal is only used to demodulate the controlinformation. Specifically, the UE performs accurate synchronizationand/or radio resource management measurement (including measurement onreference signal receiving power, reference signal receiving quality,and the like) by using a CRS that is periodically sent on the firstcarrier, for example, a CRS with a cycle of 5 ms (such as CRSs insubframe 0 and subframe 5). However, assuming that the foregoingdemodulation reference signal in the first subframe can use a resourceposition of the CRS, the demodulation reference signal in the firstsubframe is only used for demodulation, for example, is only used fordemodulation of the control information in the control region, and isnot used for the accurate synchronization and/or radio resourcemanagement measurement.

Optionally, a time-frequency position and/or a sequence of thedemodulation reference signal is the same as that of a cell-specificreference signal CRS defined in an LTE system earlier than release 11.

Optionally, an antenna port corresponding to the demodulation referencesignal is all or a part of antenna ports 7 to 10 in the LTE system,where the antenna ports 7 to 10 are antenna ports corresponding to auser equipment-specific reference signal.

Optionally, the control information and/or the demodulation referencesignal is sent in a part of bandwidths of the first carrier.

Optionally, the receiving module 82 is further configured to: beforereceiving the control information, sent by the network device, in thecontrol region of the first subframe of the first radio frame, scrambleor interleave the PDCCH in the control region by using a virtual cellidentifier.

The receiving module 82 is further configured to receive a secondePDCCH, sent by the network device, in a second subframe of the firstradio frame. The second subframe may be a subframe except the firstsubframe in the radio frame.

Optionally, the receiving module 82 is further configured to: beforereceiving the control information, sent by the network device, in thecontrol region of the first subframe of the first radio frame, receive aposition of the control region that is notified by the network device,where the first subframe includes multiple control regions, and themultiple control regions are frequency-multiplexed.

The receiving module 82 is further configured to: before at least onefirst subframe is determined in at least one radio frame on the firstcarrier, receive RRC dedicated signaling sent by the network device,where the RRC dedicated signaling is used to indicate a position of thefirst subframe of the first radio frame on the first carrier.Specifically, one obtaining manner is: obtaining from the network devicewhich subframe of the first radio frame is the first subframe, where thefirst radio frame is any radio frame, a bitmap manner may be used as thespecific obtaining manner. For example, if the first radio frame has 10subframes, 10 bits are used to indicate the first subframes separately.This manner is also applicable when the number of subframes of the firstradio frame differs. For example, if there are eight subframes, eightbits are used for indication. Another obtaining manner is: obtainingfrom a cycle of the first subframe and a position of the first subframein the cycle that are indicated by the network device. For example, ifthe cycle is two radio frames, that is, 20 subframes, and positions ofthe first subframe in this cycle are subframes 0 and 1 of radio frame 0,the positions are subframes 0 and 1 of radio frames 2, 4, 6, and so on,in a next cycle. This manner is more flexible than the first manner, andbetter matching with PMCH subframes can be implemented because a PMCHhas the largest demand for the first subframe.

The receiving module 82 is further configured to receive thedemodulation reference signal, sent by the network device, in thecontrol region of the first subframe of the first radio frame.

For example, the first subframe is one or more types of the followingsubframes: an MBSFN subframe, a subframe bearing a CSI-RS, specialsubframes in TDD special subframe configurations 0 and 5, and a physicalmulticast channel subframe. Alternatively, if a broadcast message is notconfigured with an MBSFN subframe, the UE receives only the secondePDCCH; and if a broadcast message is configured with an MBSFN subframe,the network device may obtain the first subframe and receive the PDCCHor the first ePDCCH in the first subframe.

Optionally, the determining module is further configured to: before thereceiving module receives the first ePDCCH in the control region of thefirst subframe of the first radio frame, determine a resource block RBgroup of the first ePDCCH in the control region, where the RB groupcorresponds to one RB pair, and the RB pair is a resource assignmentunit of a physical downlink shared channel PDSCH in the LTE system; anddetermine a first candidate resource of the first ePDCCH in the RBgroup, where the first candidate resource includes a part of or all ofresources of each RB of at least two RBs, and the at least two RBsbelong to the RB group; and the receiving module is specificallyconfigured to receive the first ePDCCH in the control region of thefirst subframe of the first radio frame in the following manner:receiving the first ePDCCH in the at least two RBs or in the RB group towhich the first candidate resource belongs.

Optionally, the determining module is further configured to determine anantenna port corresponding to the first ePDCCH. Specifically, theantenna port corresponding to the first ePDCCH may be determinedaccording to the first candidate resource. Specifically, the antennaport may be determined according to a resource position of the firstcandidate resource, for example, a position of a part of resources inone RB corresponds to antenna port 7, and a position of another part ofresources corresponds to antenna port 8; the antenna port may also bedetermined according to a resource unit number or a resource position ofthe first ePDCCH, where the resource unit is at least one of an RB pair,an RB, an ECCE, an eREG, and an RE that form the first ePDCCH; and theantenna port may also be configured through RRC dedicated signaling, andspecially, a port may be randomly selected, and then configured for theUE through the RRC signaling.

The receiving module is specifically configured to receive the firstePDCCH in the control region of the first subframe of the first radioframe in the following manner: on the antenna port corresponding to thefirst ePDCCH, for the first ePDCCH and the demodulation reference signalthat are corresponding to a same antenna port, receiving the firstePDCCH by using a same precoding vector or precoding matrix.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, the determining module is further configured to: before thereceiving module receives the first ePDCCH in the control region of thefirst subframe of the first radio frame, determine a resource set of thefirst ePDCCH in the control region, where the resource set includesmultiple resource block RB groups, each RB group of the multiple RBgroups corresponds to one RB pair, and the RB pair is a resourceassignment unit of a physical downlink shared channel PDSCH in the LTEsystem; and determine a second candidate resource of the first ePDCCH inthe resource set, where the second candidate resource includes a part ofor all of resources of each RB group of at least two RB groups, and theat least two RB groups are RB groups of the multiple RB groups; and

the receiving module is specifically configured to receive the firstePDCCH in the control region of the first subframe of the first radioframe in the following manner: receiving the first ePDCCH in the atleast two RB groups included in the second candidate resource.

Optionally, the determining module is further configured to determine anantenna port corresponding to the first ePDCCH. Specifically, theantenna port corresponding to the first ePDCCH may be determinedaccording to the second candidate resource. Specifically, the antennaport may be determined according to a resource position of the secondcandidate resource, for example, a position of a part of resources inone RB corresponds to antenna port 7, and a position of another part ofresources corresponds to antenna port 8; the antenna port may also bedetermined according to a resource unit number or a resource position ofthe first ePDCCH, where the resource unit is at least one of an RB pair,an RB, an ECCE, an eREG, and an RE that form the first ePDCCH; and theantenna port may also be configured through RRC dedicated signaling, andspecially, a port may be randomly selected, and then configured for theUE through the RRC signaling.

The receiving module is specifically configured to receive the firstePDCCH in the control region of the first subframe of the first radioframe in the following manner: in each RB group included in the secondcandidate resource, for the first ePDCCH and the demodulation referencesignal that are corresponding to a same antenna port, the first ePDCCHis received by using a same precoding vector or precoding matrix.

Optionally, the RB group corresponds to one RB pair, where the RB pairis a resource assignment unit of the second ePDCCH, and the RB pair isalso a resource assignment unit of a PDSCH resource in the LTE.Specifically, the size of the resource in the RB group may be understoodas comparable to the size of the resource in an RB pair, that is, theirsizes are approximately equal. The RB group may also be called a PRBbinding group because PRB binding can be implemented in this group toimprove channel estimation performance.

Optionally, the RB group may correspond to an RB pair for resourceassignment of the second ePDCCH in an extended cyclic prefix scenario.For example, four RBs may be included, where every two RBs correspond toone enhanced control channel element eCCE, and one eCCE corresponds toone antenna port, that is, there are two antenna ports in total, such asports 7 and 8.

Optionally, the determining module is further configured to: before thereceiving module receives the first ePDCCH, sent by the network device,in the control region of the first subframe of the first radio frame,determine a third candidate resource bearing the first ePDCCH in thecontrol region, where the third candidate resource includes resources inat least two resource block RBs; and determine an antenna portcorresponding to the first ePDCCH borne on the third candidate resource.Specifically, the antenna port corresponding to the first ePDCCH may bedetermined according to the third candidate resource. Specifically, theantenna port may be determined according to a resource position of thethird candidate resource, for example, a position of a part of resourcesin one RB corresponds to antenna port 7, and a position of another partof resources corresponds to antenna port 8; the antenna port may also bedetermined according to a resource unit number or a resource position ofthe first ePDCCH, where the resource unit is at least one of an RB pair,an RB, an ECCE, an eREG, and an RE that form the first ePDCCH; and theantenna port may also be configured through RRC dedicated signaling, andspecially, a port may be randomly selected, and then configured for theUE through the RRC signaling.

The receiving module is specifically configured to receive the firstePDCCH in the control region of the first subframe of the first radioframe in the following manner: if any proper subset of the thirdcandidate resource not capable of transmitting any complete ePDCCH, orif any two proper subsets of the third candidate resource are notcapable of transmitting any two complete ePDCCHs separately by using asame antenna port, in the resources in the at least two RBs, for thefirst ePDCCH and the demodulation reference signal that arecorresponding to a same antenna port, the first ePDCCH is received usinga same precoding vector or precoding matrix.

Optionally, the determining module is further configured to obtain anantenna port mode from the network device, where the antenna port modeis a single-antenna-port mode in units of enhanced control channelelement eCCEs, or a two-antenna-port mode in units of resource elementREs. Specifically, the antenna port corresponding to the first ePDCCH isan antenna port used to transmit the first ePDCCH, so the antenna portcorresponding to the first ePDCCH corresponding to the antenna port modemay be understood as an antenna port used to transmit the first ePDCCHand corresponding to the above single-antenna-port mode or dual antennaport mode.

The functions of the above modules are described in the embodimentcorresponding to FIG. 4, and details are not repeated herein.

As shown in FIG. 9, an apparatus provided in this embodiment may furtherinclude an RRC connection module 83.

The RRC connection module 83 is configured to: before the RRC dedicatedsignaling sent by the network device is received, receive systeminformation sent by the network device, where the system information isscheduled by an ePDCCH scrambled by a system information radio networktemporary identifier SI-RNTI; send random access information to thenetwork device, where configuration information of the random accessinformation is obtained from the system information; receive randomaccess response information sent by the network device, where the randomaccess response information is scheduled by an ePDCCH scrambled by anRA-RNTI; and receive RRC connection setup information sent by thenetwork device.

The functions of the above modules are described in the embodimentcorresponding to FIG. 5, and details are not repeated herein.

An embodiment of the present invention further provides a controlinformation sending apparatus, including a processor, a sender, amemory, and a bus.

The processor, the sender, and the memory implement mutual communicationthrough the bus.

The processor is configured to execute a computer program instruction.

The memory is configured to store the computer program instruction.

The computer program instruction is used to:

determine a first subframe of a first radio frame on a first carrier,where the first subframe includes a control region, the control regionis in first n symbols of the first subframe, and n is a natural numberless than 5;

through the sender, send control information in the control region ofthe first subframe of the first radio frame to a user equipment, andsend a demodulation reference signal in the first subframe of the firstradio frame to the user equipment, where the control informationincludes a PDCCH; and

send an ePDCCH in a second subframe of the first radio frame to the userequipment through the sender, where the second subframe may be asubframe except the first subframe in the first radio frame.

Optionally, in the sending a demodulation reference signal in the firstsubframe to the user equipment, the demodulation reference signal issent only when the control information is sent; and/or, the demodulationreference signal is only used to demodulate the control information.

The computer program instruction is further used to:

send RRC dedicated signaling to the user equipment through the sender,so as to indicate a position of the first subframe of the first radioframe on the first carrier to the user equipment.

The apparatus further includes a receiver.

The computer program instruction is further used to:

before the sender sends the RRC dedicated signaling to the userequipment, send system information to the user equipment through thesender, where the system information is scheduled by an ePDCCH scrambledby a system information radio network temporary identifier SI-RNTI;receive random access information sent by the user equipment, whereconfiguration information of the random access information is obtainedfrom the system information; send random access response information tothe user equipment, where the random access response information isscheduled by an ePDCCH scrambled by an RA-RNTI; and send RRC connectionsetup information to the user equipment.

Optionally, the control information further includes a PHICH and/or aPCFICH.

Optionally, the control information and/or the demodulation referencesignal is sent in a part of bandwidths of the first carrier.

Optionally, a time-frequency position and/or a sequence of thedemodulation reference signal is the same as that of a cell-specificreference signal CRS defined in an LTE system earlier than release 11.

The computer program instruction is further used to:

send the demodulation reference signal in the control region of thefirst subframe of the first radio frame to the user equipment throughthe sender.

Optionally, before the control information is sent in the control regionof the first subframe of the first radio frame to the user equipment,the PDCCH in the control region is scrambled or interleaved by using avirtual cell identifier.

Optionally, before the control information is sent in the control regionof the first subframe of the first radio frame to the user equipment,the user equipment is notified of a position of the control region,where the first subframe includes multiple control regions, and themultiple control regions are frequency-multiplexed.

Optionally, the first subframe is one or more types of the followingsubframes: an MBSFN subframe, a subframe bearing a CSI-RS, specialsubframes in TDD special subframe configurations 0 and 5, and a physicalmulticast channel subframe.

An embodiment of the present invention further provides a userequipment, including a processor, a receiver, a memory, and a bus.

The processor, the receiver, and the memory implement mutualcommunication through the bus.

The processor is configured to execute a computer program instruction.

The memory is configured to store the computer program instruction.

The computer program instruction is used to:

determine a first subframe of a first radio frame on a first carrier,where the first subframe includes a control region, the control regionis in first n symbols of the first subframe, and n is a natural numberless than 5;

through the receiver, receive control information, sent by a networkdevice, in the control region of the first subframe of the first radioframe, and receive a demodulation reference signal, sent by the networkdevice, in the first subframe, where the control information includes aPDCCH; and

receive an ePDCCH, sent by the network device, in a second subframe ofthe first radio frame through the receiver, where the second subframemay be a subframe except the first subframe in the radio frame.

Optionally, in the receiving a demodulation reference signal, sent bythe network device, in the first subframe, the demodulation referencesignal is sent only when the control information is sent; and/or, thedemodulation reference signal is only used to demodulate the controlinformation.

Optionally, before the first subframe of the first radio frame on thefirst carrier is received, RRC dedicated signaling sent by the networkdevice is received through the receiver, where the RRC dedicatedsignaling is used to indicate a position of the first subframe of thefirst radio frame on the first carrier.

Optionally, before the RRC dedicated signaling sent by the networkdevice is received, system information sent by the network device isreceived, where the system information is scheduled by an ePDCCHscrambled by a system information radio network temporary identifierSI-RNTI; random access information is sent to the network device, whereconfiguration information of the random access information is obtainedfrom the system information; random access response information sent bythe network device is received, where the random access responseinformation is scheduled by an ePDCCH scrambled by an RA-RNTI; and RRCconnection setup information sent by the network device is received.

Optionally, the control information further includes a PHICH and/or aPCFICH.

Optionally, the control information and/or the demodulation referencesignal is sent in a part of bandwidths of the first carrier.

Optionally, a time-frequency position and/or a sequence of thedemodulation reference signal is the same as that of a cell-specificreference signal CRS defined in an LTE system earlier than release 11.

Optionally, the computer program instruction is further used to receive,through the sender, the demodulation reference signal, sent by thenetwork device, in the control region of the first subframe of the firstradio frame.

Optionally, the computer program instruction is further used to, beforereceiving the control information, sent by the network device, in thecontrol region of the first subframe of the first radio frame, receive,through the receiver, a position of the control region that is notifiedby the network device, where the first subframe includes multiplecontrol regions, and the multiple control regions arefrequency-multiplexed.

Optionally, the computer program instruction is further used to, beforereceiving the control information, sent by the network device, in thecontrol region of the first subframe of the first radio frame throughthe receiver, scramble or interleave the PDCCH in the control region byusing a virtual cell identifier.

Optionally, the first subframe is one or more types of the followingsubframes: an MBSFN subframe, a subframe bearing a CSI-RS, specialsubframes in TDD special subframe configurations 0 and 5, and a physicalmulticast channel subframe.

Persons of ordinary skill in the art may understand that all or a partof the steps of the foregoing method embodiments may be implemented by aprogram instructing relevant hardware. The foregoing program may bestored in a computer readable storage medium. When the program runs, thesteps of the foregoing method embodiments are performed. The foregoingstorage mediums include various mediums capable of storing program code,such as a ROM, a RAM, a magnetic disk, or an optical disc.

Finally, it should be noted that, the foregoing embodiments are merelyintended for describing the technical solutions of the present inventionrather than limiting the present invention. Although the presentinvention is described in detail with reference to the foregoingembodiments, persons of ordinary skill in the art should understandthat, they may still make modifications to the technical solutionsdescribed in the foregoing embodiments or make equivalent replacementsto some technical features thereof, as long as these modifications orreplacements do not cause the essence of corresponding technicalsolutions to depart from the scope of the technical solutions of theembodiments of the present invention.

What is claimed is:
 1. A control information sending method, comprising:determining, by a network device, a first subframe of a first radioframe on a first carrier, wherein the first subframe comprises at leasttwo control regions, each of the control regions is in first n symbolsof the first subframe, and n is a natural number less than 5, the numberof symbols within the first subframe is 12 or 14; notifying, by thenetwork device, a user equipment of positions of the control regions,wherein the at least two control regions are frequency-multiplexed;sending, by the network device, control information in at least one ofthe control regions of the first subframe of the first radio frame tothe user equipment, and sending a demodulation reference signal in thefirst subframe to the user equipment, wherein the control informationcomprises at least one physical downlink control channel (PDCCH).
 2. Themethod according to claim 1, wherein the demodulation reference signalis sent only when the control information is sent; and/or, thedemodulation reference signal is only used to demodulate the controlinformation.
 3. The method according to claim 1, wherein before thedetermining a first subframe of a first radio frame on a first carrier,the method further comprises: sending, by the network device, radioresource control (RRC) dedicated signaling to the user equipment, so asto indicate a position of the first subframe on the first carrier to theuser equipment.
 4. The method according to claim 1, wherein the controlinformation and/or the demodulation reference signal is sent on a partof bandwidths of the first carrier.
 5. The method according to claim 1,wherein the sending a demodulation reference signal in the firstsubframe to the user equipment comprises: sending the demodulationreference signal in the control region to the user equipment.
 6. Acontrol information receiving method, comprising: determining, by a userequipment, a first subframe of a first radio frame on a first carrier,wherein the first subframe comprises at least two control regions, eachof the control regions is in first n symbols of the first subframe, andn is a natural number less than 5, the number of symbols within thefirst subframe is 12 or 14; receiving positions of the control regionsthat is notified by the network device, wherein the at lease two controlregions are frequency-multiplexed; receiving, by the user equipment,control information, sent by a network device, in at least one of thecontrol regions of the first subframe of the first radio frame, andreceiving a demodulation reference signal, sent by the network device,in the first subframe, wherein the control information comprises atleast one physical downlink control channel (PDCCH).
 7. The methodaccording to claim 6, wherein the demodulation reference signal is sentonly when the control information is sent; and/or, the demodulationreference signal is only used to demodulate the control information. 8.The method according to claim 6, wherein before the determining a firstsubframe of a first radio frame on a first carrier, the method furthercomprises: receiving, by the user equipment, radio resource control(RRC) dedicated signaling sent by the network device, wherein the RRCdedicated signaling is used to indicate a position of the first subframeof the first radio frame on the first carrier.
 9. The method accordingto claim 6, wherein the control information and/or the demodulationreference signal is sent on a part of bandwidths of the first carrier.10. The method according to claim 6, wherein the receiving ademodulation reference signal, sent by the network device, in the firstsubframe comprises: receiving the demodulation reference signal, sent bythe network device, in the control region.
 11. A network device,comprising: a processor, configured to determine a first subframe of afirst radio frame on a first carrier, wherein the first subframecomprises at least two control regions, each of the control regions isin first n symbols of the first subframe, and n is a natural number lessthan 5, the number of symbols within the first subframe is 12 or 14; atransceiver, configured to notify the user equipment of positions of thecontrol regions, wherein the at least two control regions arefrequency-multiplexed; and the transceiver if further configured to sendcontrol information in at least one of the control regions of the firstsubframe of the first radio frame determined by the processor, and senda demodulation reference signal in the first subframe to the userequipment, wherein the control information comprises at least onephysical downlink control channel (PDCCH).
 12. The device according toclaim 11, wherein the transceiver is configured to send the demodulationreference signal in the first subframe to the user equipment in thefollowing manner: sending the demodulation reference signal only whenthe control information is sent; and/or sending the demodulationreference signal, which is only used to demodulate the controlinformation, in the first subframe to the user equipment.
 13. The deviceaccording to claim 11, wherein the transceiver is further configured tosend radio resource control (RRC) dedicated signaling to the userequipment, so as to indicate a position of the first subframe of thefirst radio frame on the first carrier to the user equipment.
 14. Themethod according to claim 11, wherein the control information and/or thedemodulation reference signal is sent on a part of bandwidths of thefirst carrier.
 15. The device according to claim 11, wherein thetransceiver is specifically configured to send the demodulationreference signal in the control region of the first subframe of thefirst radio frame to the user equipment.
 16. A user equipment,comprising: a processor, configured to determine a first subframe of afirst radio frame on a first carrier, wherein the first subframecomprises at least two control regions, each of the control regions isin first n symbols of the first subframe, and n is a natural number lessthan 5, the number of symbols within the first subframe is 12 or 14; atransceiver, configured to receive positions of the control regions thatis notified by the network device, wherein the at least two controlregions are frequency-multiplexed; and the transceiver is furtherconfigured to receive control information, sent by a network device, inat least one of the control regions of the first subframe determined bythe processor, and receive a demodulation reference signal, sent by thenetwork device, in the first subframe, wherein the control informationcomprises at least one physical downlink control channel (PDCCH). 17.The user equipment according to claim 16, wherein the demodulationreference signal is sent only when the control information is sent;and/or, the demodulation reference signal received in the first subframeby the transceiver is only used to demodulate the control information.18. The user equipment according to claim 16, wherein the transceiver isfurther configured to: before the processor determines the firstsubframe in the first radio frame on the first carrier, receive radioresource control (RRC) dedicated signaling sent by the network device,wherein the RRC dedicated signaling is used to indicate a position ofthe first subframe of the first radio frame on the first carrier. 19.The method according to claim 16, wherein the control information and/orthe demodulation reference signal is sent on a part of bandwidths of thefirst carrier.
 20. The user equipment according to claim 16, wherein thetransceiver is specifically configured to receive the demodulationreference signal, sent by the network device, in the control region ofthe first subframe of the first radio frame.